----- Original Message -----
From: "Hamish Moffatt" <hamish@xxxxxxxxxxxx>
To: <ethereal-dev@xxxxxxxxxxxx>
Sent: Wednesday, December 19, 2001 4:17 AM
Subject: Re: [Ethereal-dev] Searching for packets with incorrect checksums
> On Tue, Dec 18, 2001 at 04:27:03PM -0600, Jim Fleming wrote:
> > stuff that belongs in Layer 3 (TCP|UDP) not Layer 2 (IP), and they
>
> When did all the layers get renumbered?
>
> Last time I checked, TCP/UDP was layer 4 and IP layer 3.
>
> Hamish
> --
> Hamish Moffatt VK3SB <hamish@xxxxxxxxxx> <hamish@xxxxxxxxxxxx>
>
Yes, you are correct, when numbering from 1 and using the OSI layers.
It may be better to use names rather than numbers (i.e. Network and Transport).
People may also think in terms of the packet structure, MAC...IP....TCP|UDP...
but...MAC addresses are not always involved....and now with Link Local notions
there is an IP layer which is really more like the MAC Layer (i.e. Layer 2)....
some people now speak of Layer 2.5 and 3.5....because they see that IP is pulled
down in the ARP mess....which should be Layer 1 but is Layer 2 in your numbering...
--------
Layer 7: The application layer...This is the layer at which communication partners are identified, quality of service is identified,
user authentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the
application itself, although some applications may perform application layer functions.)
Layer 6: The presentation layer...This is a layer, usually part of an operating system, that converts incoming and outgoing data
from one presentation format to another (for example, from a text stream into a popup window with the newly arrived text). Sometimes
called the syntax layer.
Layer 5: The session layer...This layer sets up, coordinates, and terminates conversations, exchanges, and dialogs between the
applications at each end. It deals with session and connection coordination.
Layer 4: The transport layer...This layer manages the end-to-end control (for example, determining whether all packets have arrived)
and error-checking. It ensures complete data transfer.
Layer 3: The network layer...This layer handles the routing of the data (sending it in the right direction to the right destination
on outgoing transmissions and receiving incoming transmissions at the packet level). The network layer does routing and forwarding.
Layer 2: The data-link layer...This layer provides synchronization for the physical level and does bit-stuffing for strings of 1's
in excess of 5. It furnishes transmission protocol knowledge and management.
Layer 1: The physical layer...This layer conveys the bit stream through the network at the electrical and mechanical level. It
provides the hardware means of sending and receiving data on a carrier.
---
Getting back to the point, DiffServ and IntServ should not be in the IP Layer
they should be in the [TCP|UDP] Layer.
BTW....With IPv16 there is no ARP....and no version number wasting space in the header...
...speed is the goal....
This may help...
http://www.dot-biz.com/IPv4/Tutorial/
http://www.RepliGate.net
The Netfilter Project: Packet Mangling for Linux 2.4
http://netfilter.samba.org
Jim Fleming
http://www.IPv8.info
IPv16....One Better !!
